SEEDING CLOVERS OR GRASSES INTO OLDER ALFALFA BENEFITS AND HAZARDS ABSTRACT INTRODUCTION

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1 SEEDING CLOVERS OR GRASSES INTO OLDER ALFALFA BENEFITS AND HAZARDS STANDS- Mick Cnevri1, Dn Putnm2, Brbr Reed3, Rchel Long4, Steve Orlo~, Tom Lnini6, nd Lrry Godfrey7 ABSTRACT Deciding wht to do with n older stnd of lflf is often difficult decision. A crown stnd of 3-5 plnts per squre foot in field four to five yers old myor my not be profitble for one more seson. growers would like to hve options vilble to insure dditionl yields nd profits in the finl yer of production. INTRODUCTION This pper will discuss the most current reserch in progress being conducted in the centrl nd northern prts of the stte. Two studies completed in 1995 evluted the benefits of interseeding berseem nd red clover, orchrdgrss nd ots on the Dvis cmpus reserch frm. The Stockton site ws five yer old stnd nd included 20 cre berseem interseeding on October 1994, nd red clover interseeded on 20 cres in October The yields were tken during the 1995 growing seson. Preprtion on both sites included light hrrowing in October to remove weeds nd brek the soil crust to enhnce seed bed. Forge legumes nd grsses were drill plnted between ~ nd 1" in depth. The Stockton site ws irrigted up in October of 1994 nd the Dvis site ws rinfll germinted. The following lists the prctices completed for both sites: 1 Corresponding Author: Mick Cnevri, Fnn Advisor, University of Cliforni Coopertive Extension, 420 S. Wilson Wy, Stockton, CA Forge Specilist, UC Dvis; 3 Fnn Advisor, Glenn County; 4 Fnn Advisor, Yolo County; 5 Fnn Advisor, Siskiyou County; 6 Weed Specilist, UC Dvis; 7 Entomology Specilist, UC Dvis. l 22

2 /, PROCEDURES Pest popultions were below norml through most of the lflf growing seson. This is probbly due to the cool wet conditions during the seson. In the Dvis tril the berseem, ots nd orchrdgrss plots hd fewer weevils thn the lflf lone which suggests tht weevils prefer lflf to the overseeded forges. Although weevil counts were lower with the sweep net method in the overseeded plots, selective feeding to the lflf ws observed resulting in significnt dmge to lflf, s seen in Tble I. The berseem nd red clover hd miniml weevil feeding injury nd high yields. These legumes my eliminte the need for weevil insecticide tretment. Aphid counts were low through the growing seson, verging two per sweep t the Dvis site. Even with the lower phid numbers there still ws trend for lower popultion in the overseeded tretments of ots nd berseem. cterpillr nd rmyworm popultions incresed to the highest numbers by August, s shown in Tble 3. At this dte the lowest popultions were found in the berseem, ots nd orchrdgrss plots, indicting nonpreference for these forge species. Yields were significntly incresed over the lflf lone with berseem clover nd ots. Higher yields ws the trend t both sites when red clover ws interseeded into lflf (Tbles 4 nd S). Yield lone cnnot be the only fctor to consider since some of the tretments showed high percentge of weeds either erly or lte in the seson in Tble 6. For the erly seson winter weeds present t first cutting time, green chop hrvest my be necessry.herbicide lterntives for winter weed control is limited with overseeding prctices. A herbicide experiment ws conducted t the Stockton site with selected tretments listed on Tble 7. Velpr nd Pursuit showed excellent weed control with good crop sfety but poses soil crryover limittion if the lflf is to be removed the sme yer nd plnted to nother crop. Grmoxone ws used t the ~ pt rte on the 20 cre berseem nd clover field. This very low rte helped control smll weeds nd kept the 1 st cutting clen but lso reduced the yield of berseem clover t the 1 st cutting by 10%. The high rte of Grmoxone of. 5 Ib i or 2 pts/cre in the herbicide tril reduced or killed 75% of the berseem. Qulity of forges ws mesured t the Stockton site for the June hrvest. Results listed on the Qulity Anlysis chrt shows the crude protein, TDN nd the ADF. Smples were tken from bles t the stck compred to fresh smples in the field. The qulity of red clover plus lflf ws similr to lflf in the ble. Berseem + lflf showed cceptble crude protein but higher in fiber thn other forges s shown in the ADF column. 23

3 Tble 1 Percent Egyptin Weevil Dmge to vs. Clover in the Overseeded Plots t UC Dvis Tretment check spryed Red clover Orchrdgrss Ots2 Weevil Count * * 0. 00* % Dmge * * % Clover Dmge * 12.09* 1 Dmge ws determined by collecting lflf nd clover stems from i ech plot nd ssessing percentge of tissue loss. 2 Sweep net not effective on ots * Overseed tretments were significntly different fr~!!l-the Check. p <.05 Tble 2 Aphids by Dte nd Tretment t UC Dvis Tretment check spryed Red clover Orchrdgrss Ots 3/7/ /28/ *, 8/2/ * 8 17* Numbers of insects per 10 sweeos 24

4 Tble 6 Weeds s Percent of the Totl DM by Dte nd Tretment t UC Dvis Tretment check spryed Red Clover Orchrdgrss Ots 4/5/ b bc c 6/5/ " -'. 57 7/5/ b 4.85 b 2.63 b 3.66 b O b bcd s with different letters re significntly different t p <.05 25

5 ;j t Tble 7 Herbicide Tretment nd Yield Dt on Berseem Clover + Rte I st Hrvest 2nd Hrvest 3rd Hrvest 4th Hrvest Tretment lbl i Grmoxone c 2888 cd 2662 bc 781 b Pursuit b Surfctnt Pursuit b 4949 b 2985 b 626 b Velpr TR-IO Velpr + TR-IO b 5034 b 3098 b 697 b Check (Berseem b 4711 b 2493 bc 645 b + lflf t SUMMARY Higher yields cn be obtined by overseeding berseem or ots into n lflf stnd on the finl yer of production. It ws lso noted tht once these crops hd diminished by mid seson so hd the lflf stnd. It should be understood tht selecting either berseem or ots is for short term gin to mximize yield production for two or three cuttings only nd then to remove the lflf. Red clover or orchrdgrss did not give the sme short term yield boost but my produce better qulity feed (less weeds) throughout the entire seson. Red clover nd orchrdgrss, being perennils, continue to grow during the summer months, competing more effectively ginst mid to lte seson weeds. Both of these forge types will lso resume growth the following yer. It is importnt tht grower fully understnd the benefits nd hzrds tht differ between vrious forge legumes or grsses before engging into the overseeding concept. Once understood, the opportunity to overseed certin grsses or legumes cn be useful in developing certin niche mrkets while incresing production nd lowering pest control cost in older lflf stnds. l 26