SynopsisMaximum yields on low nitrogen soils resulted from the application of 20 pounds of N per acre for every 3 inches of available preplanting soil moisture. Flour of inferior protein quality was milled from wheat grown under high moisture stress. N recovery increased from 30 to 50% as available soil moisture at seeding time increased from O to 8 inches. Water use and water use efficiency increased as available soil moisture and rate of N fertilization increased.

SynopsisNitrogen fertilization caused increases in the grain yield, number of culms per plot, plant height, and straw weight of all varieties. None of the varieties showed an effect on the calculated number of kernels per head. The effects of fertilization on 100-kernel weight, heading date, test weight, and straw-grain ratio were variable.

SynopsisCulms per square foot, height, and vigor in the fall were much affected by seeding rate, row spacing distance, fertilizer rate, and fertilizer placement while yield, lodging score, and test weight were less affected. However, the positive correlation between fall culm count and yield in 3 of the 4 experiments emphasizes the importance of selection, of proper row spacing distance, seed rate, fertilizer rate, and fertilizer placement for producing winter wheat in Michigan.

Dry aggregate soil structure and relative structural stability were compared for various crop rotations, straw residue placements, and methods of summer fallow tillage under dryland conditions. The proportion of nonerodible aggregates was greater when a straw residue was returned to the soil than when it was burned or partially removed. The increase in aggregation attributed to the residue was higher when the residue was left on the surface than when it was plowed under. The proportion of aggregates > 0.84 mm. in diameter was higher when fallow was initially tilled with the moldboard plow than when it was tilled with a one-way disk or sweep implement. The inclusion of grasses and legumes in rotation with winter wheat and fallow resulted in a lower proportion of nonerodible aggregates than under the more common wheat-fallow rotation.

v | ok | Kirjasto Aj-K | Tähkän morfologisten ominaisuuksien vaikutus syysvehnän tähkäidäntäherkkyyteen

In studying the susceptibility of winter wheat to sprouting in the ear attention was paid at the Experimental Farm of the Plant Breeding Institute of Hankkija to the importance of the ear type. This was done by using two methods parallelly: HÄNSEL’s sandbed method, which shows the genetic susceptibility of the varieties; and the »nature method» which elicits the effect of ear type. The results led to the following conclusions: Both methods gave similar results, indicating that the differences in genetic susceptibility to sprouting in the ear (between the varieties) are so great that they emerged by both methods used. The classification of the material into four groups, hairy erect, hairy nutant, bald erect and bald nutant, showed that the ear type has its own importance as a factor reducing sprouting. The bald ear was found to be better than the hairy and the nutant superior to the erect ear. The disadvantage of hairy ears is obviously connected with their greater water-retaining capacity. Owing to this they germinate more readily, especially in conditions in which the water capacity of the ears is only occasionally optimal for sprouting as is often the case in the field during the ripening period when the weather keeps changing.

In studying the susceptibility of winter wheat to sprouting in the ear attention was paid at the Experimental Farm of the Plant Breeding Institute of Hankkija to the importance of the ear type. This was done by using two methods parallelly: HÄNSEL’s sandbed method, which shows the genetic susceptibility of the varieties; and the »nature method» which elicits the effect of ear type. The results led to the following conclusions: Both methods gave similar results, indicating that the differences in genetic susceptibility to sprouting in the ear (between the varieties) are so great that they emerged by both methods used. The classification of the material into four groups, hairy erect, hairy nutant, bald erect and bald nutant, showed that the ear type has its own importance as a factor reducing sprouting. The bald ear was found to be better than the hairy and the nutant superior to the erect ear. The disadvantage of hairy ears is obviously connected with their greater water-retaining capacity. Owing to this they germinate more readily, especially in conditions in which the water capacity of the ears is only occasionally optimal for sprouting as is often the case in the field during the ripening period when the weather keeps changing. | Syysvehnän tähkäidäntäherkkyyttä selvitettäessä on Hankkijan koetilalla kiinnitetty huomiota myös tähkätyypin merkitykseen tähkäidäntään vaikuttavana tekijänä. Asiaa selvitettiin käyttämällä rinnan kahta menetelmää: HÄNSELin hiekkalaatikkomenetelmää, joka osoittaa lajikkeiden geneettisen herkkyyden, sekä »luonnon menetelmää», jossa tähkätyypin vaikutus pääsi esille. Tulosten vertailu johti seuraaviin päätelmiin: Molemmilla menetelmillä saatiin samansuuntaisia tuloksia, mikä osoittaa, että geneettiset (lajikkeiden väliset) tähkäidäntäherkkyyserot ovat niin suuria, että ne saadaan selville molemmilla käytetyillä menetelmillä. Materiaalin jako neljään ryhmään: karvaiset pystyt, karvaiset nuokkuvat, kaljut pystyt ja kaljut nuokkuvat osoitti, että tähkätyypillä on myös oma merkityksensä idäntää edistävänä tai estävänä tekijänä. Kalju todettiin karvaista edullisemmaksi ja nuokkuva pystyä paremmaksi. Karvaisten tähkien epäedullisuus on ilmeisesti yhteydessä niiden suuremman vedenpidätyskyvyn kanssa. Tästä johtuen ne itävät herkemmin varsinkin olosuhteissa, missä tähkien kosteustila on itämisen kannalta vain ajoittain optimissa, niinkuin pellolla tuleentumisaikana sään vaihdellessa usein sattuu.