Vegetables being a rich source of vitamins, minerals and non-nutritive phytochemicals play a vital role in our diet. According to World Health Organization, lower intake of vegetables is one of the main risk factors for mortality. To make a healthy diet affordable to all, the gap between actual and potential yield of vegetables should be reduced. Foliar application of water soluble fertilizers can boost production in vegetables thus attaining the goal of food security. Foliar applied nutrients absorbed through stomata and cuticle. For better results, foliar application of nutrients at proper growth stage of crop is important. It is not an alternative to soil application, but supplement soil application especially when secondary and micro nutrient deficiencies arise. In spite of a few limitations foliar nutrition serves as an efficient means of nutrient management in vegetables. To combat the wide spread deficiencies of nutrients especially arising at the critical stages of crop growth foliar nutrition can be successfully adopted.

Background: Legumes are one of the major sources of dietary proteins for the people of India and is an inevitable component of vegetarians’ diet. Among them cowpea pods and seeds are rich source of protein and accrue delicacy in cuisines. Adequate amounts of fertilizers applied through most effective and economic means can raise productivity and profitability of cowpea cultivation. Hence the present study was formulated with an objective to study the effect of water-soluble macro and micro nutrient fertilizers on nodulation, quality and nutrient uptake of vegetable cowpea. Methods: Field experiment was conducted at Coconut Research Station, Balaramapuram during the period from 12 November 2020 to 31 January 2021. The experiment was laid out in randomized block design with 13 treatments in 3 replications. The treatments comprised of recommended dose of fertilizers (RDF) as control and RDF + foliar application of NPK 19:19:19 (0.5%) or potassium nitrate (0.5%) alone or in combination with ZnSO4 (0.05 %) and solubor (0.025%). Result: Foliar nutrition of micro and macro nutrients had significant effect on nodulation, quality and nutrient uptake. Foliar nutrition of 19:19:19 resulted in the production of higher number of nodules than KNO3. Among the treatments, RDF (20:30: 10 kg NPK ha-1) + foliar application of 19:19:19 (0.5% ) + solubor (0.025% ) at 45 DAS resulted in higher number of nodules and nodule fresh weight per plant, however higher number of effective nodules was recorded in RDF + foliar nutrition of 19:19:19 (0.5%) alone at 45 DAS. The highest uptake of N, P and K by the crop was also recorded in RDF + foliar application of 19:19:19 (0.5%) + solubor (0.025%) at 45 DAS. Zinc uptake was the highest in RDF + foliar application of KNO3 (0.5%) 45 and 60 DAS and B uptake was the highest in RDF + foliar application of KNO3 (0.5%) + solubor (0.025%) at 45 DAS. The highest crude protein content was recorded in RDF + foliar nutrition of 19:19:19 (0.5%) + ZnSO4 (0.05%) and solubor (0.025%) at 45 DAS fb 19:19:19 (0.5%) at 60 DAS. The treatment, RDF + foliar application of 19:19:19 (0.5%) + solubor (0.025%) at 45 DAS resulted in the highest number of pods and green pod yield per plant in bush type vegetable cowpea.

Background: Cowpea is a leguminous crop of indeterminate growth habit and continues to produce flowers throughout its life cycle. In order to realize the genetic yield potential of cowpea, nutrient requirements of later formed flushes also needs to be met. Hence the present study was formulated to assess the effect of foliar application of water-soluble macro nutrient fertilizers viz., NPK 19:19:19 and potassium nitrate and micronutrient fertilizers viz. zinc sulphate and solubor for yield maximization in bush vegetable cowpea. Methods: The field experiment was conducted at Coconut Research Station, Balaramapuram, during Rabi 2020-21. The experiment was laid out in randomized block design with 13 treatments in three replications. The treatments comprised of recommended dose of conventional fertilizers (RDF) NPK 20:30:10 kg ha-1 as control and RDF + foliar application of water-soluble fertilizers 19:19:19 (0.5%) and potassium nitrate (0.5%) with zinc sulphate (0.05%) and solubor (0.025%) in twelve different combinations. Result: Results revealed that compared to RDF alone, RDF + foliar application of water-soluble macro and micro nutrient fertilizers at 45 DAS significantly improved the dry matter production, number of pods per plant and pod weight and recorded a yield enhancement of 22 to 55 per cent. Among the treatments, RDF + foliar application of 19:19:19 (0.5%) and solubor (0.025%) at 45 DAS recorded the highest dry matter production per plant (39.51 g), pods per plant (30.88 no.), pod yield (7410 kg ha-1), net return (82651 Rs ha-1) and B:C ratio (2.26). The treatments, RDF + foliar application of 19:19:19 (0.5%) at 45 DAS; RDF + foliar application of 19:19:19 (0.5%), zinc sulphate (0.05%) and solubor (0.025%) at 45 DAS; and RDF + foliar application of potassium nitrate (0.5%) and solubor (0.025%) at 45 DAS also recorded comparable number of pods per plant, green pod yield, net return and B:C ratio. Considering the highest green pod yield, net return and B:C ratio, RDF + foliar application of NPK 19:19:19 (0.5%) and solubor (0.025%) at 45 DAS could be recommended for yield maximization in bush type vegetable cowpea.