Comparative Assessment of Effects of Genotypes on Growth Parameters of Spider Plant between Greenhouse and Outdoor Systems
Kenneth Mutoroα & Kalio S. Wasikeσ
The supply of spider plant (Cleome gynandra L.) as one of the African leafy vegetables in Kenya is low and this is attributed to limited access by farmers to improved varieties. This study was carried out to evaluate the comparative effect of different accessions on growth of spider plant in greenhouse and outdoor systems. Greenhouse and outdoor experiments were conducted in 2011 and 2012 in Juja and Ruiru sub counties of Kiambu county, Kenya. The main objective was: to determine the influence of spider plant genotypes on plant growth variables, and compare the two production systems of outdoor and greenhouse. The 4 lines that were developed at the World Vegetable Centre, Arusha, were evaluated alongside the commercial variety, P6 (control). Plants were harvested at 6 and 9 weeks old, and both plant height and leaf area estimated. Data was analyzed in SAS 9.1.3 software. Accessions were ranked from 1-5 in terms of performance. Results indicated that UGSF14 and MLSF17 produce more leaf area and tall plants compared to all other genotypes under the outdoor system. The study recommended that farmers should grow improved spider plant varieties under outdoor system rather than in the greenhouse in order to realize more yields.
Keywords: African leafy vegetables, cleome gynandra, manure, cultivars.
Authorα: Department of Horticulture and Food Security, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
σ: Kalio S. Wasike (Masinde Muliro University of Science & Technology Kakamega, Kenya).
Spider plant (Cleome gynandra L.) is amongst the most preferred African leafy vegetables (ALVs) in the tropics. It contains numerous vitamins, minerals and bioactive phytochemical compounds for nutritional and health benefits. Most of the ALVs can considerably contribute to requirements of vitamin A and iron, both critical nutrients for developing countries (Jaarsfeld et al., 2014). Studies have shown that spider plant is among the African leafy vegetables whose consumption has grown steadily in Kenya. Its health and economic benefits have been explored extensively in the recent past (Ojiewo et al., 2010). However, limited access by farmers to improved spider plant varieties is a major cause of low fresh leaf yields for this crop. To further improve production, plant nutrition through use of nitrogen rich organic manure is also important. Nitrogen is a vital mineral element for plant growth which affects not only the biomass accumulation but also the nutritional quality of higher plants. Nitrogen is an important nutrient that is constituent of amino acids, proteins and DNA that are part cell division. Additionally, it is a major component of chlorophyll that is the backbone of photosynthesis.
Mineral fertilizer releases nitrogen faster than manure, which is a slow release thus, takes more time to mineralize in the soil. In principle, manure-nitrogen will be available to the plants for a longer period due to lower prevalence to leaching and/or volatilization. Besides nitrogen, manure also has other important plant nutrients that are essential for plant growth. Manure is an important source of essential plant nutrients and organic matter for crop production (Ogendo et al., 2008). It leads to improved soil physical properties, water holding capacity, cation exchange capacity (Ng’etich et al., 2012). Nutrients in manure are released over a long period of time, which can be up to three years (Herman, 2011). Manure also reduces soil carbon to nitrogen ratio that facilitates speedy nitrification (Brady, 1984). Previous research has shown that application of nitrogen increased fresh and dry above-ground biomass in leafy vegetables between levels of 100-250kg N/ha (van Averbeke et al., 2007). Yields are also being improved through selection of genotypes of spider plant, which has intensified in the recent past (Onim and Mwaniki, 2008; Masinde, 2011), considering that commercial varieties have shortfalls with regard to yield, nutrient, and geographical diversity. Limited access to quality seed and shortage of suitable cultivars has been key cause of low spider plant productivity (Abukutsa-Onyango, 2010b). Commercial farmers apply nitrogen fertilizer in order to obtain higher yields of spider plant (Agong and Masinde, 2006). Mauyo et al. (2008) have shown that applying nitrogen fertilizer significantly increased plant height, number of leaves and shoots, and fresh yields (p≤0.05), which is either organic or inorganic. Use of inorganic and organic fertilizers significantly improved yields of Brassica oleracea var oleracea (Wambani et al. 2006). However, nitrogen phytotoxity can be harmful to human health (Blom-Zandstra, 2008). Although it was not a component of this study, literature has shown that higher crop yields were obtained when organic and inorganic sources were combined (Herman, 2011). Vorster and Rensburg (2005) and Mtambanengwe et al. (2006) observed that N availability from low quality organic materials can be improved with the integration of inorganic fertilizer.
- MATERIALS AND METHODS
Greenhouse and outdoor experiments were carried out in order to evaluate, select and document spider plant varieties’ agronomic performance. Experiments were conducted in neighboring Juja and Ruiru sub counties situated in Kiambu county, Kenya, between March-June 2011 and April-July 2012; its geographical coordinates are latitude 1° 9' 0" S, and longitude 36° 58' 0" E. The area is classified under sub-tropical highland climate, by Köppen climate classification system, receives average annual rainfall of 1,025 mm. Temperature range is 10-26°C with altitude of 1,795 m above sea level. The soils are typically red on undulating topography. Main human activities include coffee farming, dairy, and horticulture (MoA, 2008). The experimental factors tested consisted of five spider plant genotypes. The genotypes included: P6; MLSF17; UGSF9; UGSF14 and UGSF36. Both experiments were laid out as a complete randomized design (CRD) with three replications. Analyses of variance (ANOVA) were done using SAS (SAS 9.1.3) for height and leaf area of spider plant. The level of significance was at p<5% and mean separation was done using LSD.
- RESULTS AND DISCUSSION
3.1 Effect of genotypes on plant height across harvesting periods in outdoor and greenhouse.
Genotypes significantly influenced the height of spider plant across different harvesting periods between greenhouse and outdoor experiment (Table3.1). UGSF 14 had the tallest and significance plant under outdoor system in the sixth week of harvesting compared to the other four genotypes. MLSF 17 was the second in plant height after UGSF14. However, in the 9th week of harvesting MLSF 17 had the tallest plant height compared to all other genotypes while UGSF14 and UGSF36 had the second tallest crop among the group. In the greenhouse production system, there was no significance difference in the height of the plant between different genotypes at both the 6th and 9th week of harvesting (Table 3.1). Genotypes produced tall plants when planted in the outdoor than when planted in the greenhouse environment (Table 3.1). The above findings can be attributed to the inability of spider plant being unable to produce better yields due to restrictions in the greenhouse condition such as nutrients, root expansion and micro climate (Jaarsfeld et al., 2014). In the outdoor system, plants were not planted in polythene bags and hence root development and absorption of nutrients was not limited. This further indicates that spider plant is not suited for greenhouse production and hence its productivity is compromised when planted in the greenhouse than compared when planted in the outdoor production system.
Table 3.1: Effect of genotypes on plant height across different harvesting periods in outdoor and greenhouse production systems
Genotypes 6 9 6 9
MLSF17 9.22b 81.33a 14.78a 46.78a
UGSF14 11.44a 70.22b 13.67a 42.56a
UGSF36 10.11ab 68.44b 14.67a 45.22a
UGSF9 10.56ab 76.22ab 14.11a 50.33a
P6 9.89ab 74.78ab 14.33a 46.33a
LSD 1.534 6.63 1.559 6.017
CV% 8.4 9.6 4.3 18.9
Means in a same column followed by different letter (s) are significantly different at P<0.05.
3.2 Effect of genotypes on plant leaf area across different harvesting periods in outdoor and greenhouse systems.
Genotypes significantly influence the leaf area of spider plant across different harvesting periods (Table 3.2). In the 6th week of harvesting, there was no significance difference between the leaf areas of spider plant among the five genotypes evaluated under outdoor production system. There was a significance difference in the leaf area of spider plant between difference genotypes at the 9th week of harvesting under the outdoor system. MLSF17 had the largest leaf area under the outdoor system in the 9th week of harvesting compared to all other genotypes; all other four genotypes had no significance difference in their leaf area. There was no significant difference in the leaf area of various genotypes of spider plant and across harvesting periods under greenhouse production system (Table 3.2).
In the 9th week of harvesting, genotypes produced the largest leaf area under outdoor production system compared to the greenhouse production system at the same time. Similarly, the results indicate that spider plant will produce more leafy material when grown in the outdoor system than when grown in the greenhouse environment. The probable reason for the differences being attributed to imbalance in supply of both nutrients due to micro-climate in the greenhouse where evapotranspiration is limited compared to the outdoor condition (Albright, 2002).
Table 3.2: Effect of genotypes on plant leaf area across harvesting periods in outdoor and greenhouse systems
Genotypes 6 9 6 9
MLSF17 49.75a 1239.3a 44.74a 185.8a
UGSF14 46.83a 929.4b 39.31a 172.4a
UGSF36 35.22a 895.7b 44.02a 135.5a
UGSF9 38.79a 915.2b 45.26a 157.7a
P6 41.2a 961ab 43.71a 179.3a
LSD 14.51 206.5 10.19 56.02
CV% 22.7 32.9 3.1 56.3
Means in a same column followed by different letter (s) are significantly different at P<0.05.
- CONCLUSION AND RECOMMENDATIONS
There is higher nutrient use efficiency for spider plant when planted in the outdoor system compared to the greenhouse environment. MLSF17 and UGSF14 produce the tallest plants compared to all other genotypes when planted in the outdoor system. Under greenhouse conditions, all genotypes will produce similar heights and leaf area.
The number of leaves and total lea area are significantly influenced by the genotypes’ characteristics. MLSF17 and UGSF14 produce the largest amount of leaf surface area compared to all other genotypes when planted in the outdoor system.
The present study thus, recommends that breeders and eventually, farmers should adopt UGSF14 and MLSF17 in order to realize more yields from spider plant cultivation. Furthermore, emphasis should be in production of spider plant under outdoor system compared to the greenhouse environment. The conclusion agrees with Albright (2002), who reported that greenhouse environment affects wind and
humidity that in turn, influence evapotranspiration and pollination.
I wish to sincerely acknowledge National Council of Science, Technology and Innovation for funding the project. Also, Jomo Kenyatta University of Agriculture and Technology Department of Horticulture and Food Security for providing land for trials and laboratory facilities. Finally, World Vegetable Centre, (Arusha, Tanzania), for providing the spider plant seed accessions.
- Abukutsa-Onyango, M. (2007). The diversity of cultivated African leafy vegetables in three communities in western Kenya. African Journal of Food, Agriculture, Nutrition and Development. 7: (3).
- Albright, L.D. (2002). Controlling greenhouse environments. Acta Horticulturae. 578: 47-54.
- Alva, A. K., Paramasivam, S., Fares, A., Delgado, J. A., Mattos, D. Jr and Sajwan, K. (2008). Nitrogen and irrigation management practices to improve nitrogen uptake efficiency and minimize leaching losses. Journal of Crop Improvement. 15: (2) 369-420.
- Blom-Zandstra, M. (2008). Nitrate accumulation in vegetables and its relationship to quality. Annals of Applied Biology. 115: (3).
- Dalal, R. (1974). Effects of intercropping maize with pigeon peas on grain yield and nutrient uptake. Experimental Agriculture. 10: 3 219-224.
- Herman, M. (2011). Inorganic fertilizer vs. cattle manure as nitrogen sources for maize (Zea mays L.) in Kakamega, Kenya. Journal of Undergraduate Research at Ohio State. 2: 22.
Jaarsveld van P., Faber M., Heerden, I., Wenhold, F., Willem, Rensburg, W. J and van Averbekee. W. (2014). Nutrient content of eight African leafy vegetables and their potential contribution to dietary reference intakes. 33: 77-84.
- Masinde, W. P. and Agong, G. S. (2011). Plant growth and leaf N of spider plant under varying nitrogen supply. African Journal of. Horticultural Science. 5: 36-49.
- Mauyo, L. W., Anjichi, V. E., Wambugu, G. W. and Omunyini, M. E. (2008). Effect of nitrogen fertilizer levels on fresh leaf yield of spider plant (Gynandropsis gynandra) in Western Kenya. Scientific Research and Essay 3: (6) 240-4.
- Mtambanengwe, F. Mapfumo, P. and Vanlauwe, B. (2006). Comparative short-term effects of different quality organic resources on maize productivity under two different environments in Zimbabwe. Nutrient Cycling in Agroecosystems. 76: 271-84.
- Ng’etich, O. K., Aguyoh, J.N. and Ogweno, J. O. (2012). Effects of composted farmyard manure on growth and yield of spider plant (Cleome gynandra). Egerton University. International Journal of Science And Nature. 3: (3) 514-20.
- Ojiewo, C., Tenkouano, A., Oluoch, M. and Yang, R. (2010). The role of AVRDC (The World Vegetable Centre) in vegetable value chains. African Journal of Horticultural Science. 3: 1-23.
- Onim, M. and Mwaniki, P. (2008). Cataloguing and evaluation of available community/farmers-based seed enterprises on African indigenous vegetables (AIVs) in four ECA countries. Lagrotech consultants. Kisumu. pp 18-21.
- Vorster, H.J. and Jansen van Rensburg, W.S. (2005). Traditional vegetables as a source of food in South Africa: Some experiences. African Crop Science Conference Proceedings. 7: 669-71.
- Wambani, H., Nyambati, E. M. and Kamidi, M. (2008). Evaluation of legumes as components of integrated soil nutrient management for kale production. African Journal of Horticultural Science. 1: 91-9.
- WHO/FAO. (2012). Report of the Joint Expert Committee on Food Additives (JECFA) of the Food and Agriculture Organization of the UN/WHO and the European Commission's Scientific Committee on Food. pp 3.