Kenaf Variety by Date of Planting in Mississippi

Carl Hovermale

Information on crop varieties and planting dates is a basic requirement needed for producers. Previous work at the MAFES South Mississippi Branch showed that kenaf plantings from mid­April to early May produced good yields.

Four kenaf varieties were planted in four­row plots 20 feet long. Plantings began April 15 in 1990 and April 1 in 1991 and 1992, with later plantings every 2 weeks until June 15. A seeding rate of 10 pounds per acre was used in all trials. One pint of Treflan per acre was incorporated before planting. One quart of MSMA was post directed using a backpack sprayer for late season weed control when the kenaf was 3 feet tall.

Two 13­foot sections of row in each plot were cut at ground level and weighed. Samples were taken for moisture determination and yields converted to dry matter per acre. Five plants were selected at random from harvested plants in each plot and measured for plant height. Plants were counted at harvest to determine standing plants per acre.

1990 Results

Plants lodged per plot, percent defoliation, disease incidence, and percent lodging were not affected by planting date. Kenaf planted May 30 or before yielded more than that planted June 15 (Table 1). Plant height was related to planting dates. The taller plants were found in the earlier plots. However, the highest number of plants per acre resulted from the May 15 and 30 plantings.

Averaged over all planting dates, Everglades 71 was shorter than other varieties tested and yielded less than Roselle or RS10 but was not different from Tainung 1 Table 1). Roselle had the highest final plant stand (49,471 plants/acre). Tainung 1 had the lowest plant population (31,715 plants/acre). Disease and defoliation ratings for Roselle averaged around 10%, while othervarieties were between 73% and 98%.

There was an interaction between variety and planting date. The yield of RS10 and Tainung 1 decreased from the April 15 to April 30 planting, while the yield of Roselle and Everglades 71 increased for the same period.

Generally, with the planting dates imposed, Roselle was better adapted to this area than the other varieties. This year's data indicate that kenaf compensates very well for thin stands. One plant per 5 square feet yielded almost as much as 1 plant per 0.6 square foot. Early season damping off diseases are a serious problem with kenaf production. April 15 and 30 plantings consistently had lower stands even though the same number of seed was planted.

1991 Results

Kenaf planted April 1, 1991 was taller had thicker stems and yielded more than the other plantings (Table 2). Planting kenaf June 15 resulted in plants shorter than when planted May 15 or before and had the lowest yields. Planting after April 15 resulted in significantly lowered yields even though stem diameter and plant height were not significantly different. Planting April 15 resulted in significantly higher plant stands.

Averaged over all planting dates, there was no significant difference in height attributable to variety. RS10 and Everglades 71 had higher plant populations than Roselle, but Tainung 1 was not different from any variety. Roselle yielded less and had smaller stem diameters than the other varieties tested (Table 2). Roselle had the highest plant mortality. There was no interaction between variety and planting date for any variable studied.

Generally, with the planting dates imposed, Roselle was the least adapted to this area, which is a contradiction of the previous year's results. This difference is attributed to the lack of disease pressure. Some of the differences in plant stand are attributed to trying to adjust seeding rate for the percent seed germination of each variety.

1992 Results

In 1992, Kenaf planted June 15 was shorter, had thinner stems, and yielded less than the other plantings (Table 4). Planting April 15 resulted in significantly higher yields than planting May 15 or after even though plant height was not significantly different. Planting May 15 resulted in significantly higher plant stands (Table 3).

Averaged over all planting dates, there was no significant difference in height or yield attributable to variety. Roselle had higher plant populations than Tainung 1 and Everglades 71 but was not different from RS10 (Table 3). Roselle had smaller stem diameters and lower plant populations than the other varieties (Table 4). There was no difference in mortality attributable tovariety. There was no interaction between variety and planting date for any variable studied.

1993 Results

Kenaf planted May 1, 1993 or earlier was taller, had greater stem diameters, and yielded more than the other plantings (Table 5). Plant stand was variable. Kenaf planted April 15, May 15, and June 15 had higher populations than kenaf planted April 1 or May 1 (Table 6). Kenaf planted May 15 had the lowest yield and smallest stem diameter. Tainung 1 was taller, had thicker stems, and yielded more than Roselle (Table 6). There was an interaction between variety and planting date for stem diameter, but it was relatively small and extremely variable.

Table 1. Effect of variety and planting date on kenaf yield,

MAFES South Mississippi Branch, 1990.

Variety 

­­­­­­­­­­-------------lb/acre­­­­­­­­­­­­­­-------------------




Date        RS10   Everglades 71   Tainung 1 Roselle    Average
April 15    7,230   4,485           4,890       9,037    6,402A1
April 30    5,275   5,780           3,253       9,857    6,401A
May 15      6,266   5,443           4,579       9,483    6,443A
May 30      6,567   5,145           4,880       7,431    6,006A
June 15     3,594   4,820           2,289       2,728    3,356B 
Average     5,786B  5,129C          3,976C      7,707 
1 Means within a column followed by the same letter are not different at
the (p<.05) level of significance according to DMRT.

Table 2. Effect of variety and planting date on kenaf yield,

MAFES South Mississippi Branch, 1991.

Variety
Date      RS10    Everglades 71 Tainung 1 Roselle    Average---Lb/acre-----



April 1   14,027  15,635        14,647    11,082     13,853A1
April 15  12,322  12,477        13,562     9,222     11,896B
May 1     8,990   11,005        10,850     7,827     9,668C
May 15    9,377   9,765          9,920     7,517     9,145C
June 1    9,222   10,695         9,300     7,285     9,125C
June 15   7,052   4,052          6,897     5,192     6,549D 
Average   10,165A 11,108A      10,862A     8,021B

1 Means within a column followed by the same letter are not different at the (p<.05) level of significance according to DMRT.

Table 3. Effect of variety and planting date on kenaf final plant stand, MAFES South Mississippi Branch, 1992.

Variety
Date        RS10     Everglades 71 Tainung 1 Roselle Average----total plants/acre-----



April 1     17,820   49,950        15,390    46,440   32,400B1

April 15    28,080   33,210        12,960    49,680   30,983B
May 1       31,050   23,490        24,030    32,400   27,743B
May 15      88,560   56,700        73,980    88,020   76,816A
June 15     42,930   23,490        36,180    65,070   41,917B
Average     41,688AB 37,368B       32,508B   56,322A

1 Means within a column followed by the same letter are not different at the (p<.05) level of significance according to DMRT.

Table 4. Effect of variety and planting date on kenaf yield, MAFES South Mississippi Branch, 1992.

Variety
Date         RS10   Everglades 71 Tainung 1 Roselle  Average-----lb/acre
      
April 1      10,462  15,810       11,625    19,142   14,260AB
April 15     17,825  15,267       15,035    17,050   16,294A
May 1        16,042  15,112       15,267    12,245   14,667AB
May 15       11,005  14,492       14,260    12,090   12,962B
June 15       8,292   8,060        9,532     6,742    8,157C 
Average      12,725  13,748       13,144    12,725

1 Means within a column followed by the same letter are not different at the (p<.05) level of significance according to DMRT.

Table 5. Effect of variety on kenaf plant height, population,

yield, and stem diameter, MAFES South Mississippi Branch, 1993. 

                             Plant                            Stem
Variety       Height         Population         Yield         Diameter 
                In           Plants             lb/A          mm

RS 10          114B          42,000A            6,572A        7.40B
Everglades 71  109BC         23,211C            5,438AB       7.9AB 
Tainung 1      128A          30,333BC           6,988A        9.00A
Roselle        102C          39,875AB           4,655B        5.70C
Mean           113           33,855             5,913         7.5

1 Means within a column followed by the same letter are not different at the (p<.05) level of significance according to DMRT.

Table 6. Effect of planting date on kenaf plant height, population, yield, and stem diameter, MAFES South Mississippi Branch, 1993.

Planting Plant Stem 

Date         Height            Population        Yield        Diameter 
              in               plants/A           lb/A          mm
April 1      128.40A1          24,083C           8,979A        10.0A
April 5      123.6AB           41,938AB          7,858A        8.4AB
May 1        118.4AB           21,533C           5,675B        9.7AB
May 5         98.4C            40,063AB          2,712C        3.6C
June 1       110.4BC           28,867BC          5,544B        7.6B
June 15      102.0C            45,938A           5,548B        5.7C
Mean         113.5             33,737            6,052         7.5

1 Means within a column followed by the same letter are not different at the (p<.05) level of significance according to DMRT.

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Carl H. Hovermale is Agronomist at the South Mississippi Branch Experiment Station, Poplarville, MS.