Effect of Sowing Date on the Development of Lacy Phacelia (Phacelia Tanacetifolia Benth.)

Abstract

Experiments with lacy phacelia (Phacelia tanacetifolia Benth.) were carried out in the period 2017-2021, during which the effect of sowing date on the stand development was assessed (height, coverage, accomplishment of individual growth stages, and weed infestation). It was demonstrated that the sowing date affects the stand growth and development. In earlier sowing dates, plants developed slower than in later sowing dates but reached a greater average height (926 mm). The lowest height (802 mm) was exhibited by plants from May (sowing 3). The third sowing date also showed the worst stand canopy closure and at BBCH 31, the stand canopy closure in Sowing 1, 2, and 3 was 82.3%, 77.8%, and 67%, respectively. The third sowing date was also the highest weed infestation. The effect of sowing date on yield and yield parameters was also monitored (weight of a thousand of grains and germinative capacity). Based on the measured data, it can be concluded that the influence on the weight of thousands of grains was minimal and in germinative capacity. Significant differences were recorded only in first year in which the germinative capacity of plants from the later sowing dates was reduced.

Keywords: growth and height intensity; phacelia; sowing date; weed infestation; yield parameters.

Figure A1

Number of plants per m²—Sowing 1 (12th of April) in 2018 (A) and leaf coverage in %—Sowing 1 (12th of April) in 2018 (B).

Figure A2

Number of plants per m²—Sowing 2 (24th of April) in 2018 (A) and leaf coverage in %—Sowing 2 (24th of April) in 2018 (B).

Figure A3

Number of plants per m²—Sowing 3 (10th of May) in 2018 (A) and leaf coverage in %—Sowing 3 (10th of May) in 2018 (B).

Figure A4

Number of plants per m²—Sowing 1 (5th of April) in 2019 (A) and leaf coverage in %—Sowing 1 (5th of April) in 2019 (B).

Figure A5

Number of plants per m²—Sowing 2 (16th of April) in 2019 (A) and leaf coverage in %—Sowing 2 (16th of April) in 2019 (B).

Figure A6

Number of plants per m²—Sowing 3 (7th of May) in 2019 (A) and leaf coverage in %—Sowing 3 (7th of May) in 2019 (B).

Figure A7

Number of plants per m²—Sowing 1 (8th of April) in 2020 (A) and leaf coverage in %—Sowing 1 (8th of April) in 2020 (B).

Figure A8

Number of plants per m²—Sowing 2 (22nd of April) in 2020 (A) and leaf coverage in %—Sowing 2 (22nd of April) in 2020 (B).

Figure A9

Number of plants per m²—Sowing 3 (7th of May) in 2020 (A) and leaf coverage in %—Sowing 3 (7th of May) in 2020 (B).

Figure A10

Average daily temperatures and daily precipitation amounts in the growing seasons of period 2018–2020. The values were measured by the professional meteorological station (ID: B2TROU01; type: AKS2) which is operated by the Czech Hydrometeorological Institute.

Figure A11

Organization of the field experiment: I (A,B,C)—Sowing 1 (1st half of April); II (A,B,C)—Sowing 2 (2nd half of April); III (A,B,C)—Sowing 3 (May).

Figure 1

Illustration of the growth stages in which lacy phacelia plants were evaluated. BBCH 00—sowing; BBCH 12–98—ten terms of measurements (height—evaluated in all terms; coverage of phacelia—evaluated in terms BBCH 10, 12, 16, 31, 51, 61, and 72; coverage of weeds and number of plants per m² for the lacy phacelia and for individual weed species were evaluated in BBBCH 61).

Figure 2

Effect of sowing date on the number of days for reaching the respective developmental stages. Mean values (n = 9) of individual variants are shown for the specific developmental stage (BBCH) in three years of study ± SD. Different letter indices are present only in variants in which significant differences were found (p < 0.05). If no letter indices are included, no significant difference was found between the respective variants.

Figure 3

Effect of sowing date on the number of days for reaching the range of developmental stages. Mean values (n = 9) of individual variants are shown for the specific range of developmental stages (BBCH) in three years of study ± SD. Different letter indices are present only in variants in which significant differences were found (p < 0.05). If no letter indices are included, no significant difference was found between the respective variants.

Figure 4

Effect of sowing date of the height of plants reached in the respective developmental stages. Average values (n = 90) of individual variants are shown for the specific developmental stages (BBCH) in three years of study ± SD. Different letter indices are added only to variants in which significant differences were found (p < 0.05). If there are no letter indices, no significant differences between the individual variants were found.

Figure 5

Effect of sowing date on average daily height increment reached between the respective developmental stages BBCH. Average values (n = 90) of individual variants are shown for the specific range of BBCH developmental stages in three years of study ± SD. Different letter indices are added only to variants in which significant differences were found (p < 0.05). If there are no letter indices, no significant differences were found between the individual variants.

Figure 6

Effect of sowing date on the coverage of plants reached in individual developmental stages. Average values (n = 9) of individual variants are shown for the specific developmental stages (BBCH) in three years of study ± SD. Different letter indices are added only to variants in which significant differences were found (p < 0.05).

Figure 7

Effect of sowing date on average daily increment of coverage reached between individual BBCH developmental stages. Average values (n = 9) of individual variants are shown for the specific range of BBCH developmental stages in three years of study ± SD. Different letter indices are added only to variants in which significant differences were found (p < 0.05). If there are no letter indices, no significant differences were found between the individual variants.

Figure 8

Localization of the experimental plot at Agricultural Research Ltd. In the Czech Republic and EU.