Pima Regional Variety Test at the Maricopa Agricultural Center, 1997

Abstract

Eighteen Pima varieties were grown in a replicated trial 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 data are presented in this report.

Introduction

This trial was conducted to evaluate Pima varieties and experimental strains under central Arizona conditions. Varieties from the USDA and private seed companies were included. This trial was part of the national cotton variety testing program with S-7 designated as the national standard and OA 312 and S-6 being regional standards.

Materials and Methods

This trial 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 four rows wide, 43 feet long, with 40 inch spacing. The field was preirrigated on 20 March and seed 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 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 trial are shown in Table 1. Yields ranged from 463 to 1430 lbs lint/acre. The 1997 cotton growing season was characterized by heavy Lygus infestations. Three and four year averages of lint yields are presented in Tables 2 and 3, respectively. Fiber properties (HVI) are listed in Table 4.