The effect of different levels of metribuzin and water application on the growth and yield of lentils ( Lens culinaris Medik.) : a dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours in the University of Canterbury [Lincoln College]

Abstract

Lentils c. v. 'titore' were sown in November 1987. A factorial combination of metribuzin rates (0.088, 0.175 and 0.263 kg a.i. ha⁻¹) and water application rates (200, 400, 600 and 800 1 ha⁻¹) was applied when plants were 8 - 10 cm tall. Total dry matter, seed yield and chlorophyll a and b content were determined along with plant parameters such as yield components, plant vigour and plant height. Visible signs of early herbicide damage such as chlorosis, leaf bum and stunted growth occured, but significant responses were not able to be measured quantitatively. Seed yield and total dry matter were not affected by herbicide or water rates and the mean yields were 2170 kg ha⁻¹ and 4190 kg DM ha⁻¹ respectively. Chlorophyll a content was 3 - 5 times greater than chlorophyll b content but total chlorophyll content was not affected by herbicide or water rate. Seeds pod⁻¹ decreased from 1.50 to 1.44 at 0.088 and 0.175 kg a.i. ha⁻¹ but this did not alter the harvest index which remained at 52 % . In experiment 2, 'titore' lentils were grown in pots in a glasshouse and five metribuzin rates were applied (0 - 1.05 kg ha⁻¹) when the plants were 8 cm tall. Dry matter declined linearly with increase in herbicide rate from 0.40 to 0.17 g pot⁻¹ (R² = 85.6% ).