Upland Regional Cotton Variety Test at the Maricopa Agricultural Center, 1997

Abstract

Thirty four upland cotton varieties were grown at the Maricopa Agricultural Center as part of the national cotton variety testing program. Lint yield, boll size, lint percent, plant population and fiber property are presented in this paper.

Introduction

An upland cotton variety test was conducted as part of the national cotton variety testing program. This program allows varieties from many sources to be evaluated at various locations across the cotton belt. Included in the test were four national standards, sixteen regional standards and fourteen other varieties from across the cotton belt. The national standards are grown in five other tests across the cotton belt. The national standards are Maxxa, Paymaster HS 26, SG 125 and STV LA 887.

Materials and Methods

This test was located in a level basin field with 850 foot runs and was arranged in a randomized complete block design replicated five times. Plots were 4 rows wide, 43 feet long, with 40 inch spacing. The field was preirrigated on 20 March and seed was planted in moist soil on 10 April. Additional irrigations were on 30 April, 19 May, 5 June, 20 June, 2 July, 14 July, 24 July, 4 August, 15 August and 5 September. The cotton received 120 lbs/acre of nitrogen during the season. Orthene and Knack was applied on 23 July, Lannate and Lockon on 12 August, Lockon and Orthene on 21 August, and Applaud and Penncapp on 29 August. The planting was defoliated on 29 September and 6 October and the center two rows of each plot were machine harvested on 29 October. Heat units (threshold 86/55 degrees F) for the growing season were 4161 and rainfall during the period (10 April to 29 September) was 1.87 inches. Fifty hand picked boll samples taken out of two reps were used to determine lint percent and boll size. The same sample was ginned and twenty grams of lint was analyzed for fiber properties.

Results and Discussion

Results of the test are shown in Table 1. Yields ranged from 879 to 1503 lbs lint/acre. The 1997 cotton growing season was characterized by heavy Lygus infestations. Three and four year averages of lint yield of some varieties are represented in Tables 2 and 3, respectively. Fiber properties (HVI) are listed in Table 4.