Impact of basin irrigation on black pepper production in coffee based cropping system in high altitude regions of Kodagu, Karnataka.

摘要

Experiments were conducted at high altitude (1000 m above MSL) in coffee based cropping system in two plantations in Kodagu, Karnataka. The basin irrigation @ 50-60 litres per vine was given through hose after harvest from March 15th onwards once in 15 days up to May 15th in irrigated block and the quantity of water was adjusted based on the rainfall of preceeding week. In irrigated area, new leaves and spikes emerged uniformly in May last week-June first week followed by setting in June. In rainfed area, new leaves and spikes emerged in July-August. Number of spikes per m2 and number of berries per spike recorded significant variation between irrigated and rainfed treatments in both the locations. Incidence of anthracnose and spike shedding was less in irrigated vines compared to rainfed vines. At 6 metre height of vine, number of spikes per m2 was 160.9 at Boikeri and 233.8 at Hosakeri in irrigated treatment, whereas it was 32.5 at Boikeri and 51.4 at Hosakeri in rainfed treatment. Number of berries per spike doubled in irrigated vines compared to rainfed vines in both locations. Mean berry yield per vine was 6.3 kg per vine in irrigated treatment and 1.9 kg per vine in rainfed treatment. The results clearly indicate that basin irrigation of pepper vines during March-May and shade regulation in April help in early initiation of spikes and good setting. In high elevation, in an year of pre monsoon failure black pepper needs to be irrigated in summer to harvest good crop in coffee based cropping system where black pepper is a mixed crop.