**18. Standardized NPK levels for soilless vegetable production**

Liquid nutrient formulations for growing zucchini, colour cabbage, chilli, coriander, cucumber, French bean, peas, and tomato on Arka Fermented Cocopeat under open and polyhouse soilless culture have also been developed. Best nutrient scheduling under open conditions was found to register maximum growth and yield in polyhouse conditions as well.

#### **18.1 Zucchini**

Nutrient scheduling of 168 ppm N-NO3, 16 ppm P, and 189 ppm K recorded maximum fruit length (24.12 cm), fruit girth (44.4 mm), fruit weight (335.6 g), and yield (5.71 kg/plant and 71.39 t/ha) under open conditions. The above-mentioned nutrient scheduling recorded maximum growth and zucchini fruit yield in protected conditions also [25, 26].

#### **18.2 Colour/red cabbage**

Nutrient scheduling of 185 ppm N-NO3, 41 ppm P, and 210 ppm K recorded maximum stem diameter (25.71 mm), a number of leaves (24.82), head diameter (36.79 cm), head length (14.64 cm), average head weight (972.25 g/plant), and yield (54.01 t/ha). The best nutrient scheduling under protected conditions is also found to register maximum growth and red cabbage yield in open conditions [27].

#### **18.3 Chilli**

In Chilli hybrid Arka Meghana, the highest number of fruits (248.2) and yield per plant (1.43 kg) was recorded with scheduling of 176 ppm N-NO3, 29 ppm P, and 200 ppm K per plant and found to be on par with 194 ppm N-NO3, 32 ppm P, and 228 ppm K (218.6 fruits and 1.30 kg yield per plant). However, the maximum fruit length (12.22 cm), fruit girth (10.98 mm), average fruit weight (5.96 g per fruit), and dry chilli yield (287 g per plant) was recorded with 194 ppm N-NO3, 32 ppm P, and 228 ppm K nutrient scheduling [28].

#### **18.4 Coriander**

The production technology for soilless cultivation of coriander var. *Arka Isha* under open as well as in protected conditions has been standardized. The highest leaf yield of 4.79 t/ha was recorded with scheduling of 132 ppm N, 21 ppm P, and 150 ppm K under an open-field system of soilless cultivation. The performance of coriander under open field soilless culture was found to be better than polyhouse soilless culture [28].

#### **18.5 Cucumber**

Supplying of 166 ppm N-NO3, 33 ppm P, and 207 ppm K recorded the maximum stem girth (18.43 mm), highest fresh (1690 g/plant), and dry plant biomass (540.8 g/ plant), highest average fruit weight (212.9 g) and yield (2.11 kg/plant and 32.51 t/ha) under open-field conditions [31].
