Cowpea (Vigna unguiculata L.) is a widely grown legume food crop of the tropics and sub-tropics. The crop is well adapted to poor fertility and low rainfall conditions. It is grown widely throughout the year for all forms tender pods, dry seeds, green manure and cover crops both as sole and inter crop. It improves soil fertility and physical structure and considered as a suitable crop in rotation even in dry lands.
Cow pea pods are good source of fibre, minerals, calcium and vitamins particularly vitamin A and vitamin C. The nutritive value of cow pea grain, leaves and haulm is very high. The crude protein content ranges from 22 to 30 % in the grain and leaves on a dry weight. However, there is insufficient research work on impact of phosphorus levels on cow pea genotypes under this agro-climatic region. Hence, the present study was conducted.
Legumes are phosphorus loving plants. They require phosphorus for growth and seed development and most especially in nitrogen fixation which is an energy-driving process. (Sanginga et al. 2000), but this is not achievable in the tropics because of low soil fertility and poor farming practices. Soil phosphorus or depletion of the phosphorus through cultivation. For sustainable food production to meet the increasing population in developing countries, the need for phosphorus fertiliser application is expected to increase (Brynes and Bumb, 1998).
However, even when phosphorus fertiliser are applied to replenish soil fertility, about 70 to 90 % of the phosphorus fertiliser are adsorbed and becomes locked in various soil Phosphorus compounds of low solubility without giving any immediate consideration to crop production (Holford, 1997). Phosphorus although not required in large quantities is critical to cow pea yield (particularly for improved photo period-insensitive cultivars) because of its multiples effects on nutrition. It not only increases seed yields but also nodulation (Singh et al ,2011).
Some researchers also reported that phosphorus application influences the content of other nutrients in leaves and seed because of its multiple effects on plant nutrition Shilpa, (2013).
Multiple effect of phosphorus fertiliser is recommended to cow pea for;
- Helps in nodule formation
- Biosynthesis of chlorophyll
- Nitrogen fixation it can fix up to 11-20 kg N/ha
- Increase protein content.
Effect of geno-types and phosphorus levels on growth and growth attributes shows Rawati genotype was recorded maximum plant height (108.53 cm)and number of branches per plant(23.73).Baramasi genotype produced highest number of leaves per plant(87.6) with application of 40kg P2O5/ha. Maximum total dry matter accumulation (3746.41 kg/ha) observed by SB-2. In case of yield and yield all attributes show superior results in geno-type Baramasi with application of 60 kg P2O5/ha. Pod yield (5199.99 kg/ha) and seed yield (1303.72 kg/ha).
Chlorophyll a and b content (0.98 mg/g) in leaves was present maximum in Baramasi var. with 60 kg P2O5/ha and chlorophyll content in pod (0.59 mg/g) was maximum in Baramasi with application of 40kg P2O5/ha. Ascorbic acid (1.63 mg/100g) content in pods of cowpea was recorded highest in geno-type SB-2.
Generally, as a legume crop protein content in cowpea seed is 22-25% and here Baramasi gave highest protein (21.37%) content with the application of 60 kg P2O5/ha (24.87%). Nutrient content of NPK in seed (%) was recorded in genotype Baramasi with 60kg P2O5/ha with highest Nitrogen (3.42%) in seed. Phosphorus content (3.12%) and potassium content(2.03%) in seed was recorded highest in genotype Rawati with 60 kg pP2O5/ha. Increasing phosphorus levels increases micro nutrients and heavy metals are reduced with similar results were reported by (Ayeni 2017).
Finally I can conclude with my research work genotype Baramasi is giving highest yield with increasing application of phosphorus levels showing maximum effect on growth, development and yield with the application of 60 kg P2O5/ha respectively.
So It can be recommended to our farmers with application of 60 kg P2O5 per hectare will provide them highest yield in case of cowpea at Gajapati district of Odisha’s agro-climatic conditions.
Yerramsetty Sudha Rani
M.Sc. Horticulture(Vegetable Science)
MSSSOA,CUTM,Gajapati ,Odisha
Email: sudhayerramsetty081@gmail.com