Increased Number of Spikelets per Panicle Is the Main Factor in Higher Yield of Transplanted vs. Direct-Seeded Rice
Round 1
Reviewer 1 Report
L20-22: The… dry matter… under TR …enhance panicle number per m2: The panicle number per m2 does not differ between TR and SL in Table2.
L66：Sink size is defined as the number of spikelts per m2. Some researchers define sink size as the number of spikelets per m2 * one grain weight since one grain weight is determined mainly by husk size in rice. I think it is better not to use the word “sink size”.
L111: I would like to know the information about a rice variety “XD11”. Indica type or Japonica type? Hybirid or not?
L133: I am interested in the difference of root growth in figure 9. I would like to know how root weight was measured since root system develops into soil deeply.
L136: What does “the number of plants” indicate. Does the number of plants mean the number of effective tillers including main shoots plus ineffective tillers? The number of ineffective tillers seem to be difficult to count at the harvesting stage.
L248-333: I feel discussion 4.1 is too long. Both HI and total dry weight, and both grain filling rata and duration are important to determine yield. Then yield components are negatively correlated each other. AS far as I konw, HI, grain filling rate, and the number of spikelets per area are the main factor to determine the yield in many cases. Anyway, you should discuss only the difference between direct seeding and transplanting.
I agree with your idea that TR show high yield due to the heavy total dry weight. However, the heading date, the important factor determining yield, differ between transplanting and direct seeding. You should discuss the possibility that early heading, which brought high sunshine during the ripening, increased yield in TR. I mean yield in direct seeding might increase if direct seeding date and heading date became earlier.
Author Response
(1) L20-22: The… dry matter… under TR …enhance panicle number per m2: The panicle number per m2 does not differ between TR and SL in Table2.
The difference between TR and BS is mainly expressed here, and I have modified this sentence.
(2) L66：Sink size is defined as the number of spikelts per m2. Some researchers define sink size as the number of spikelets per m2 * one grain weight since one grain weight is determined mainly by husk size in rice. I think it is better not to use the word “sink size”.
At present, many scholars use the concept of "sink size" when comparing different cultivation modes or varieties (such as Peng, S.B., 2006; Yoshida et al., 2006, etc.), and we also believe that this concept is very useful in studying rice yield.
(3) L111: I would like to know the information about a rice variety “XD11”. Indica type or Japonica type? Hybirid or not?
"XD11" belongs to japonica rice, a variety obtained by conventional breeding, and is the current main variety in Xinjiang, China.
(4) L133: I am interested in the difference of root growth in figure 9. I would like to know how root weight was measured since root system develops into soil deeply.
In the area of one square meter in each plot, we first use scissors to harvest the rice shoots, and then dig the roots with shovel. (about 40 cm deep. In fact, this method is not perfect if we want to determine the morphological indexes of roots, but we just want to know the difference of root dry matter under different planting methods. Because the very fine roots in deep soil account for a small proportion of root biomass, we think this method is feasible.)
(5) L136: What does “the number of plants” indicate. Does the number of plants mean the number of effective tillers including main shoots plus ineffective tillers? The number of ineffective tillers seem to be difficult to count at the harvesting stage.
The number of plants represents the sum of effective tillers and ineffective tillers. We determine it by counting the number of stems and whether effective panicles are formed.
(6) L248-333: I feel discussion 4.1 is too long. Both HI and total dry weight, and both grain filling rata and duration are important to determine yield. Then yield components are negatively correlated each other. AS far as I konw, HI, grain filling rate, and the number of spikelets per area are the main factor to determine the yield in many cases. Anyway, you should discuss only the difference between direct seeding and transplanting.
We have revised discussion 4.1 and deleted some contents that are not closely related to planting methods.
Reviewer 2 Report
The manuscript title “Increased number of spikelets per panicle is the main factor in 2 higher yield of transplanted vs direct-seeded rice” is well written and organized. It could be potentially published in the journal if some major concerns will be corrected.
- I tried to look for the information of how many percent of each cultivation method among those 3 methods are practically applied n China or at least in that area, the information should be added in an introduction.
- I have observed in materials and methods that the crops were applied with very high rate of fertilizer. It should be indicated if the rates are applied in the common practice by farmers.
- I do not understand the statical analysis in table 2. The suitable statistic should be used combine analysis among the 3 years instead of using year as one of the factors. I think this is the most of my concern for all the analysis results.
- The footnote under table 3 should be mean in rows? Or mean in column?
- The figure 8 is interesting but it is difficult to read and understand, can the author change into histogram or table.
Author Response
(1) I tried to look for the information of how many percent of each cultivation method among those 3 methods are practically applied n China or at least in that area, the information should be added in an introduction.
At present, these three planting methods are used in China, but there is no clear information on the application proportion of the three methods in the whole China. I found the information about rice planting methods in Zhejiang Province, China, and added it to the introduction. Since Zhejiang Province is one of the most important rice planting areas in China, We believe that this information can indirectly reflect the current application of these three planting methods in China.
(2) I have observed in materials and methods that the crops were applied with very high rate of fertilizer. It should be indicated if the rates are applied in the common practice by farmers.
The amount of fertilizer applied in our field experiment was indeed determined with reference to the general application of local farmers, and was supplemented in the manuscript.
(3) I do not understand the statical analysis in table 2. The suitable statistic should be used combine analysis among the 3 years instead of using year as one of the factors. I think this is the most of my concern for all the analysis results.
Table 2 shows the overall statistical analysis results of 3-year test data.
(4)The footnote under table 3 should be mean in rows? Or mean in column?
Table 3 shows the correlation coefficient between rice yield and yield composition.
(5) The figure 8 is interesting but it is difficult to read and understand, can the author change into histogram or table.
We have changed figure 8 to a table as you suggested.
Round 2
Reviewer 1 Report
The conclusion that yield is higher in TR than in SL and BS because of its larger number of spikelets per area is not new but well known, although the idea of root growth in Fig 9 is interesting. I think, however, it is important to accumulate the information of filed experiments in agronomy. Therefore, I would like to accept this report.
Author Response
Thank you very much for your suggestions and comments.
